2021 Challenger Eckental

Country	Player	Rank1	Seed
AUS	Jordan Thompson	71	1
CZE	Jiří Veselý	78	2
AUT	Jurij Rodionov	131	3
GER	Oscar Otte	135	4
CZE	Tomáš Macháč	136	5
USA	Maxime Cressy	141	6
GER	Mats Moraing	154	7
POL	Kacper Żuk	163	8

• ¹ Rankings are as of 25 October 2021.^[1]

The following players received wildcards into the singles main draw:

• Marvin Möller
• Max Hans Rehberg
• Mats Rosenkranz

The following player received entry into the singles main draw using a protected ranking:

• Julian Lenz

The following players received entry from the qualifying draw:

• Johannes Härteis
• Christopher Heyman
• Tobias Simon
• Henri Squire

The following players received entry as lucky losers:

• Alexander Erler
• Lucas Miedler
• Aldin Šetkić

• Daniel Masur def. Maxime Cressy 6–4, 6–4.

• Roman Jebavý / Jonny O'Mara def. Ruben Bemelmans / Daniel Masur 6–4, 7–5.